Proposal Summary Neural regulation of sleep, appetite and energy homeostasis is critical to an animal's survival and under stringent evolutionary pressure. Dysregulation of sleep is strongly linked to obesity, diabetes, and metabolic disease. Despite the prevalence of disorders associated with metabolism and sleep, the neural and genetic processes that regulate interactions between these two systems is unclear. This proposal will investigate how genes and neurons modulate sleep in response to changes in metabolism. Flies, like mammals, potently modulate sleep in accordance with their nutritional needs. Specifically, flies and mammals suppress sleep in response to starvation, presumably to initiate food-seeking behavior. Powerful genetics in the fruit fly allow for precise characterization of genes regulating behavioral and metabolic processes. I recently carried out a neuron-specific RNA interference screen of over 1100 genes revealed numerous targets that are required for metabolic regulation of sleep. In particular, this screen isolated translin (trsn), an mRNA/DNA binding protein that is highly conserved from flies to humans. Neuron specific knock-down or mutations in the trsn locus results in flies that fail suppress sleep during starvation, but have normal energy stores trsn is highly conserved across phyla and has a putative role in mammalian metabolic function. This proposal seeks to characterize the cellular and neuroanatomical function of trsn to determine how sleep and metabolic state are integrated. This work will define a critical link between metabolism and sleep regulation, providing new avenues for investigating sleep-feeding interactions that potently impact human health. Functional investigation of genes regulating sleep-metabolism interactions will provide the groundwork for understanding metabolic regulation of behavior and further our understanding of obesity, sleep disorders and diabetes.